From e0ee69797db01a39c15f9a8848c780530ce179d0 Mon Sep 17 00:00:00 2001 From: Roman Khavronenko Date: Wed, 11 Aug 2021 10:51:02 +0300 Subject: [PATCH] docs: update "number of open files" tuning recommendation (#1527) * docs: update "number of open files" tuning recomendation Make "number of open files" recomendation not only Prometheus specific to avoid confusion for users who does not use Prometheus. * docs: mention fstrim in Tuning section --- README.md | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/README.md b/README.md index 22ea518c8..4bdb24c5e 100644 --- a/README.md +++ b/README.md @@ -1264,8 +1264,11 @@ or similar auth proxy. * There is no need for VictoriaMetrics tuning since it uses reasonable defaults for command-line flags, which are automatically adjusted for the available CPU and RAM resources. * There is no need for Operating System tuning since VictoriaMetrics is optimized for default OS settings. - The only option is increasing the limit on [the number of open files in the OS](https://medium.com/@muhammadtriwibowo/set-permanently-ulimit-n-open-files-in-ubuntu-4d61064429a), - so Prometheus instances could establish more connections to VictoriaMetrics. + The only option is increasing the limit on [the number of open files in the OS](https://medium.com/@muhammadtriwibowo/set-permanently-ulimit-n-open-files-in-ubuntu-4d61064429a). + The recommendation is not specific for VictoriaMetrics only but also for any service which handles many HTTP connections and stores data on disk. +* VictoriaMetrics is a write-heavy application and its performance depends on disk performance. So be careful with other + applications or utilities (like [fstrim](http://manpages.ubuntu.com/manpages/bionic/man8/fstrim.8.html)) + which could [exhaust disk resources](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1521). * The recommended filesystem is `ext4`, the recommended persistent storage is [persistent HDD-based disk on GCP](https://cloud.google.com/compute/docs/disks/#pdspecs), since it is protected from hardware failures via internal replication and it can be [resized on the fly](https://cloud.google.com/compute/docs/disks/add-persistent-disk#resize_pd). If you plan to store more than 1TB of data on `ext4` partition or plan extending it to more than 16TB,